Door bell actuated light



United StatesPatent DOOR BELL ACTUATED LIGHT Beuford W. Thomas,Princeton, W. Ya., assignor of onehalf to Clarence L. Hurt, Bluefield,W. Va.

Application January 3, 1957, Serial No. 632,301

2 Claims. (Cl- 340-377) This inventionrelates to a device toautomatically switch on a porch or entrance light when the door bell ordoor chimes switch is closed, with the light remaining on for a periodof time and then automatically turning off.

An object of the invention is to provide means which are preferably inthe nature of an attachment, for controlling a light. circuit, forexample by shunting across a manual switch in the light circuit,inresponse to energization of a door bell circuit. The attachment willbe constructed so ,that the low voltage A.C. bell circuit will triggerthe attachment whereby the comparatively high voltage light circuit willbe closed but for a short period of time. There is a delay indeenergizing the electric lamp from the time that the door bell circuitis deenergized.

With the invention applied to a dwelling, upon depression of the doorbell (or chime) button the outside porch or entrance lamp isautomatically energized providing adequate lightto secure a door key,unlock the door, gain entrance to the home without having to tumble inthe darkor be bothered with a flashlight. The lamp would remainenergized for approximately one minute in accordance with presentthoughts as to the proper time delay, this allowing suflicient time toenter, after which the lamp would automatically be deenergized. Accordingly,,no afterthought and no, manual switch operation is necessary toenergize ordeenergize the lamp. I am aware of' prior attempts to providelight in response to energization of a separate circuit. Usually, theprior devices have been constructed to aid people who do not hear very'well and do not have provision for automatically keeping the lampenergized. even after the door bell button is released but only for ashort while which. would besufiicient to enter the home. Therefore it isa further object of the invention to provide an attachment for twocircuits whereby the energization of one will exercise a controlfunction over the other circuit with the closing of the first circuiteven instantaneously causing a definite cycle of operation to occur inthe second circuit and then return to the original condition which issuch that a new cycle of operation may be commenced. Prior inventionswhich cause a signal lamp to be energized in response to energization ofanother circuit which I have experienced are quite complex in comparisonto my invention. I Therefore, it is another object of my invention toprovide. av simple circuit having only three or four components and fourterminals whereby the circuit and circuit components beingsusceptible tobe received in a box, may be easilyattached in existing dwellings or maywith equal facility be installed as original equipment.

Another specific object of the invention is to provide an attachmentthat is to be operatively connected with the low voltage A.C. bellcircuit and the higher voltage lighting circuit for energizing a lamp inthe light circuit and retaining that lamp energized for a preselectedperiod of time and automatically deenergizing that lamp in the PatentedNov. to, 1959 higher voltage circuit in response to energization of thelow voltage A.C. circuit regardless of the duration of the energizationof the low voltage circuit. Further, an object of the invention is toaccomplish these functions by exceedingly simple circuitry andcomponents capable of being supported in a small box, the circuitry andcomponents involving merely a DC. relay from one terminal of which thereextends a conductor having a rectifier of one type or another thereinand from the other terminal of which there extends a conductor withinwhich a variable resistor is applied so as to provide for manualadjustment of the time period that the relay will remain energized, andfinally, a capacitor which extends across the two conductors, oneterminal of the capacitor being connected between the rectifier and therelay while the other lead of the capacitor is connected between theThese together with other objects and advantages whichwill becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawing forming a part hereof, whereinlike numerals refer to like parts throughout, and in which:

Figure 1 is a schematic wiring diagram which shows a fragment ofa lowvoltage door bell or chime circuit v. entrance light or some other lightwhich is ordinarily together with a comparatively high voltage circuitand an attachment which energizes a lamp in the higher voltage circuitin response to a triggering impulse or continued energization of the lowvoltage circuit, and after a predetermined period automaticallydeenergizes the lamp; and

Figure 2 is a perspective view of the attachmentof Figure 1 showing theneatness with which the invention may be produced as a commercialproduct.

In the accompanying drawing there are wires 10 and 12 which representtwo sides of a typical dwelling electrical service. Electric lamp 16 isin a circuit 18 which has circuit connections with wires 10 and 12. Theelectric lamp 16 schematically represents a porch light or found in. abuilding, principally a dwelling. Switch 20 is an ordinary lightcontrolling switch in circuit 18 and is arranged to turn the light onand off by energizing or deenergizing circuit 18. The circuit 18 is acomparatively high (approximately 117 volts) A.C. circuit although othervoltages may be used depending on the particular service inthe areaWithin which the invention is practiced. The invention in no -way altersthe complete independence and use of circuit 18.

A comparatively low voltage A.C. circuit 22 is operatively connected tothe electrical service in the building represented by wires 10 and 12.Low voltage circuit 22 is a door bell or door chime circuit, the audiblesignal device 24 being shown as connected by conductors 26 and 28 to thestep down transformer 30. Transformer 30 has its terminals connected tothe wires 10 and 12 while the secondary terminals have conductors 26 and28 secured thereto. A switch 32 is interposed in conductor 28 and ispreferably of the push button type since this is most common in a bellcircuit in a dwelling.

The invention is embodied in an attachment 34 which involves anelectrical circuit and a plurality of circuit components. A casing 36(Figure 2) shows that all of the circuit components and circuitry may becontained within a small box for ease of installation and handling.

3 The function of attachment 34 is to energize circuit 18 for a shortperiod of time, the duration of which may be selected, in response toclosing switch 32, even instantaneously, regardless of the duration ofclosing switch 32. An instantaneous closing of switch 32 in low voltagecircuit 22 is all that is'necessary to cause lamp 16 to be lit andremain lit for a short period of time, say one minute, after which thelamp 16 automatically becomes deenergized. Since this lamp'is preferablya porch or entrance lamp, a person making entry into a house or avisitor will be in the light long enough to enter the house or be seen.A

The components of attachment 34 contained in the casing 36, are asensitive D.C. relay 38, a capacitor 40, a rectifying device 42 and avariable resistor 44. For one embodiment of the invention where A.C.circuit 22 is an 18 volt bell circuit, rectifier 42 will bea 100milliampereselenium rectifier, the capacitor a 1000 microfarad foilcondenser, relay 38 will have a pull in current of approximately 0.98milliampere and a fall out current of approximately 0.38 milliampere,while the variable resistor 44 will haveta'range from zero ohms to 1000ohms. However, component values may be altered. 7

Relay 38 has a coil 50 withwhich two terminals 52 and 54 are connected.An electrical conductor 56 extends frcm the first terminal 52 torectifier 42 and from rectifier 42 to the conductor 26 of low voltageA.C. circuit 22. The other terminal 54 of the coil ofthe relay isoperatively connected with the resistor 44 by conductor 60, and from theresistor 44 the conductor 60.

extends to the conductor 28 of the low voltage circuit 22.

In construction, casing 36 will be fittedwith terminals, as bindingposts 62 and 64 that will be clearly marked for the low voltageconnection with the bell circuit 22. In the schematic representation(Figure 1) wires 66 and 68 make the actual connection between bindingposts 62 and 64 and the low voltage circuit 22.

A pair of contacts 72 and 74 constitute part of the relay 38 and theyare normally open as shown in Figure 1. Thecontacts are electricallyconnected to the terminals, for example binding posts 76 and 78 whichare carried by the casing 36 and which will be marked clearly as beingthe high voltage connection. Wires 80 and 82 are attached to the bindingposts 76 and 78 and are secured in the high voltage circuit 18 in shuntwith the manually operated switch 20.

In operation, after installation asdescribed, the door bell button 32 isclosed in order to sound the signal, that is, either ring the bell orchime or whatever signal may be connected with the bell circuit 22. Thisautomatically energizes the circuit of the attachment'34 in thefollowing manner: Rectifier 42 applies DC. voltage to the coil of relay38 with the ground path being established through resistor 44. At thesame time the capacitor 40 is charged and with the energization of therelay 38 con tacts 72 and 74 are closed. Inasmuch as they are connectedin shunt with the switch 20, light 16 becomes energized by the potentialin its circuit 18.

Ordinarily a person will push the door bell button for a moment and thenrelease the same. The initial closing of switch 32 causes practicallyinstantaneous closing of contacts 72 and 74 and lighting of lamp 16.However, upon removal of the finger from the door bell button switch 32opens but the contacts 72 and 74 remain closed because relay 38continues to be energized until the energy in capacitor 40 leaks to therelay '38 and becomes dissipated. The selenium rectifier 42 during thistime prevents baclcflow of current to the signal device r 4 24.' Whenthe period of time required to dissipate the energy from capacitor haspassed, and this time may be controlled by the setting of variableresistor 44 through a shaft which-projects through casing 36, thenormally open contacts 72 and 74 are spread apart. This again opens thecircuit'lS whereby the lamp 16 is deenergized.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly, all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention asclaimed. a

What is claimed as new is as follows:

1. For use with a low voltage A.C. signal circuit and a comparativelyhigh voltage lamp circuit that has a manual switch, means responsive toinstantaneous energization of said A.C. circuit for controlling for a'period the energization of said lamp circuit by shunting saidmanualswitch, said means comprising a pair of normally open contacts connectedin shunt across said manual switch, means sensitive to energization ofsaid A.C. circuit and including a DO. circuit and connected in parallelwith said A.C. signal circuit for closing said contacts and for holdingsaid contacts closed for a period of time after said A.C.circuit isdeenergized, said D.C. circuit having a first and a second electricalconductor,a rectifier in one of said conductors, acapacitor connectedacross said conductors, an electromagnetic coil terminally connectedwith said first and second conductors, a resistor insaid secondconductor to vary said period of time, and said capacitor beingconnected to said second conductor between said A.C. circuit and saidcoil and connected to said first conductor between said rectifier andsaid coil.

2. Apparatus for automatically energizinga light for a predeterminedtime in response to actuation of a 'door bell or such comprising a highvoltage alternating current source, said light connected across saidhigh voltage a1ternating current source, a manual switch electricallyserially interposed between said source and said'light, a pair ofnormally open contacts connected in shunt across said normally opencontacts upon energization'thereof, said direct current time delay relaycircuit further including a rectifier, a capacitor, and a resistor, saidrectifier serially connected to first and second parallel'arms, saidfirst parallel arm comprising said capacitor, said second parallel armcomprising said relay coil and said variable resistor, said relay coiland said variable resistor being serially connected.

References Cited in the file of this patent UNITED STATES PATENTS FranceFeb. 7, 1951

